Washington Redskins quarterback Robert Griffin III before an NFL football game against the Cleveland Browns in Cleveland, Sunday, Dec. 16, 2012. / Rick Osentoski, AP

by Robert Klemko, USA TODAY Sports

by Robert Klemko, USA TODAY Sports

After a third day of full participation in practice, there's a "very, very good chance" Robert Griffin III will start at quarterback for the Washington Redskins against the Philadelphia Eagles on Sunday.

That's according to head coach Mike Shanahan, who says he spoke with the rookie after practice, then listed Griffin as probable this weekend.

"There doesn't look like there are any setbacks with him, but if something crazy happens, obviously, we will know before the game," Shanahan said. "I know I'm not a doctor, but he took all the reps today."

Griffin sprained his right knee in a 31-28 overtime victory over the Baltimore Ravens two weeks ago, and fellow rookie Kirk Cousins filled in last Sunday in Cleveland, leading a 38-21 victory over the Browns.

Redskins right tackle Tyler Polumbus is questionable after his concussion against the Browns. If Polumbus cannot play, Jordan Black would have likely started in his place, but Black is serving the first leg of a four-game suspension for violating the league's policy on performance enhancing substances. Former practice-squad player Tom Compton may get the start instead.

Shanahan said Polumbus' status will be a game-day decision.

The 4-10 Philadelphia Eagles have an opportunity to play spoiler as the NFC East foes renew their rivalry at Lincoln Financial Field in Philadelphia. Washington (8-6) sits in a three-way tie with the Dallas Cowboys and New York Giants for the NFC East lead. A win in Week 16, coupled with losses for the Giants, the Chicago Bears and Minnesota Vikings, would promise Washington at least a wild card berth.